diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h
index 91b26d26af8a5f..ae852add053d83 100644
--- a/arch/arm64/include/asm/cmpxchg.h
+++ b/arch/arm64/include/asm/cmpxchg.h
@@ -46,7 +46,7 @@ static inline unsigned long __xchg_case_##name(unsigned long x,		\
 	"	swp" #acq_lse #rel #sz "\t%" #w "3, %" #w "0, %2\n"	\
 		__nops(3)						\
 	"	" #nop_lse)						\
-	: "=&r" (ret), "=&r" (tmp), "+Q" (*(u8 *)ptr)			\
+	: "=&r" (ret), "=&r" (tmp), "+Q" (*(unsigned long *)ptr)	\
 	: "r" (x)							\
 	: cl);								\
 									\